Power semiconductor switches withstand a blocking voltage of several hundred Volts at high current rating. Typically, a load current through a power semiconductor switch flows in a vertical direction between the two principal planes of a semiconductor body. Gate electrodes for controlling the load current may be formed in trench gate structures extending from one of the principal planes into the semiconductor body. On the other hand, semiconductor materials with hexagonal crystal lattice such as silicon carbide and gallium nitride have seen increasing interest in the use as base material for electronic circuits.
It is desirable to improve the device characteristics and device reliability of semiconductor devices with hexagonal crystal lattice.